4.7.156 Alas, then is she drowned.] HIBBARD; Alas then, is she drown'd? F;
Alas then is she drownd. Q3; Alas, then, she is drownd. Q2;
So, she is drownde: Q1.

The format of the apparatus has several parts:

The location of the variant in the text (act, scene, line number)

The lemma, which is the portion of the text to which the note applies

A right bracket (])

The source from which the edition took its reading

A list of variants, in each case followed by the source in which the variant is found, and set off with a semicolon.

To save space, frequently cited sources are usually assigned an abbreviation called a siglum. In Shakespeare editions, F always signifies the First Folio; the second through fourth folios are referred to as F2 through F4 respectively. Similarly, Q1 is the first quarto, Q2 the second quarto, and Q3 the third.

In the example given, the first folio (F) and the three early quartos (Q1 to Q3) each have a different reading of the line in question. The editors have concluded that all four early sources are corrupt, and instead have adopted a reading suggested by G. R. Hibbard. Other editors of the play may choose a different reading of the line. The apparatus summarizes all of the textual evidence, allowing readers to assess for themselves whether the editor has made the best choice. Sometimes the editor will add a commentary, defending the choice made, explaining why other readings were rejected, or discussing how other editors have treated the passage.

This format has been used for critical apparatuses of Shakespeare and many other authors. In variorum editions, the apparatus is often placed at the bottom of the page. Sometimes a three-part format is employed, with the main text at the top of the page, textual variants in the middle, and the editor's commentary at the bottom. This remains the most common format for Shakespeare editions, although the Oxford Complete Works breaks with tradition by putting its critical apparatus in a separately published volume.

In the United States, bibliographer Fredson Bowers established a tradition of putting the critical apparatus at the back of the book, leaving the edited text clear of apparatus. This has the advantage of leaving the main text uncluttered with editorial details that may not be of interest to the general reader. However, this format is a disadvantage to scholarly readers, who are not able to see all of the textual evidence in one place.

The first printed edition of the New Testament with critical apparatus, noting variant readings among the manuscripts, was produced by the printer Robert Estienne of Paris in 1550. The Greek text of this edition and of those of Erasmus became known as the Textus Receptus (Latin for "received text"), a name given to it in the Elzevier edition of 1633, which termed it as the text nunc ab omnibus receptum ("now received by all").

The de facto standard for the representation of critical apparatus in digital scholarly editions is to follow the recommendations of the Text Encoding Initiative.[3] While other formats are also used in digital literary studies this has become the most accepted storage format.[4]